docs: def get_symop(self):
          """Returns all symmetry operations (including inversions and
          subtranslations) as a sequence of (rotation, translation)
          tuples."""
          symop = []
          parities = [1]
          if self.centrosymmetric:
              parities.append(-1)
          for parity in parities:
              for subtrans in self.subtrans:
                  for rot, trans in zip(self.rotations, self.translations):
                      newtrans = np.mod(trans + subtrans, 1)
                      symop.append((parity*rot, newtrans))
          return symop